The present invention relates to a foot securing device, particularly for ski boots.
A problem in ski boots is that of correctly securing the foot inside the boot to allow optimum transmission of forces from the foot to the ski, while skiing.
Ski boots that apply a foot securing device inside the shell, are accordingly known, such as the device disclosed in French patent published as no. 2,381,483.
This patent discloses a device that comprises a presser constituted by two jaws that laterally surround the foot and can be moved mutually closer by means of an adapted screw that interacts with them; the stem of said screw has right- and left-hand threads.
The screw can also have an eccentric-shaped head.
The drawback observed in this conventional device is constituted by the fact that in addition to being constructively complicated, is that the fine adjustment, obtained by turning the screw, depends from the quick securing, also obtained by turning the screw in order to displace the eccentric element. However, the eccentric element cannot be displaced more than a short distance because of limited lateral size.
Accordingly, once the degree of securing has been adjusted, the closure of the screw tightens the device further, forcing the skier to perform successive adjustments before achieving the desired degree of closure.
Furthermore, the securing action on the side of foot produces a discomfort or fatigue, because the lateral bones of the foot are compressed.
These lateral compressions can also cause the sole of the foot to rise by arching, and this does not allow optimum transmission of forces from the foot to the ski.
The fact is also observed that the user may inadvertently disengage the stem of the screw and the complementarily threaded seats formed on the jaws, consequently making the device unusable.
As a partial solution to some of the above-mentioned drawbacks, EP 0073991 discloses an adjustment device that comprises a bar rotatably supported by a boot. The bar can be actuated from outside, and has a first portion and a second portion with right- and left-hand threads. A first block and a second block that are movable along the bar rotatably engage with said first and second portions. One end of a first linkage and a second linkage are articulated to the blocks and, at the other end, the linkages are articulated to an adjustment device that is constituted by a plate with which a presser is downwardly associated.
Although this device allows good adjustment of the degree of pressure applied at said presser, which is usually arranged inside the shell, it still has the drawback that it allows possible mutual disengagement of the threaded bar and of the first and second blocks, consequently making the device unusable.
Moreover, every time the user puts the boot on, he must first of all engage the knob, performing a rotation that mutually spaces the first and second blocks, thus allowing to lift the presser in order to leave room for inserting the foot.
Then, once the foot has been inserted, the user must again turn the knob in the opposite direction to move the first block and the second block mutually closer, so as to achieve the desired securing of the foot.
These operations are long and not always easy.